The present invention relates generally to computer and computer peripheral equipment, and more specifically to telecommunication network equipment such as Digital Subscriber Line Access Multiplexers (DSLAMs).
The demand for access to digital communications networks, such as the Internet, is directly related to the speed or rate at which such networks can transfer data. Higher data transfer rates provide a foundation for increased communication efficiency and new types of communication applications or services. These, in turn, fuel demand for more widespread network access and still-higher data transfer rates.
Conventional analog modems currently provide a maximum data transfer rate of 56 kilobits per second (kbps). Other technologies, such as cable modem, can offer significantly improved performance, but typically require changes in a telecommunication network""s underlying architecture. Such changes may necessitate large network infrastructure investments to meet user demand for network accessibility.
Digital Subscriber Line (DSL) technology provides increased communications bandwidth while using existing twisted-pair copper lines that are prevalent throughout much of the world. DSL delivers a basic data transfer rate of 128 kbps. High speed DSL, or HDSL, can deliver a data transfer rate of 1.544 megabits per second (Mbps) in North America, and 2.048 Mbps elsewhere. Asymmetric DSL, or ADSL, can deliver data rates ranging from 1.5 to 9.0 Mbps on a downstream or receiving path, and 16 to 800 kbps on an upstream or sending path. Taken together, varying DSL technologies are referred to as xDSL.
A conventional xDSL communication network organization includes a Main Distribution Frame (MDF), an access matrix, a DSL Access Multiplexer (DSLAM) and a test unit. The MDF is coupled to the access matrix, which itself is coupled to the DSLAM and the test unit. Each of the MDF, the access matrix, the test unit, and the DSLAM reside at an xDSL service provider""s site. A set of Customer Premises Equipment (CPE) units is coupled to the MDF. Each CPE unit comprises an xDSL modem, and is located at a customer site.
The high-speed backbone is characterized by a data transfer rate much greater than that associated with any given CPE unit. Taken together, the DSLAM, the access matrix, and the MDF provide a signal exchange interface between the high-speed backbone and the CPE units. The DSLAM includes a set of xDSL modems and signal multiplexing circuitry, while the access matrix includes computer-controlled switching circuitry.
The organization of the conventional xDSL communication network as described above is undesirably space and cost inefficient. In many prior art configurations, the test unit is roughly comparable in size to the DSLAM itself.
A highly compact, cost efficient DSLAM capable of electrically characterizing subscriber loops is described in U.S. patent application Ser. No. 09/574,696, entitled xe2x80x9cDigital Subscriber Line Access and Network Testing Multiplexer,xe2x80x9d filed on May 17, 2000. The improved DSLAM system incorporates built-in hardware and/or software for measuring and/or determining subscriber loop and/or DSL network electrical characteristics. The improved DSLAM (Digital Subscriber Line Access and Network Testing Multiplexer or DSLANTM) may include a set of line cards; a set of xDSL modem cards; a redundant xDSL modem cards; a testing and switching unit; at least one control unit; at least one trunk unit; and an interface unit into which each of the aforementioned elements couples. The testing and switching unit is coupled to the redundancy bus, and includes power interface circuitry, control logic, a switching relay matrix, a memory, and a Copper Loop Tester (CLT).
The CLT includes a subscriber loop test and measurement unit, and may include a processing unit, a Digital Signal Processor (DSP), a memory, and a set of test units.
In response to commands issued by the control unit, the CLT performs tests to measure and/or determine one or more subscriber loop electrical characteristics.
The problem with the CLT is that every DSLANTM has to have a CLT, which increases the cost of the networking system.
Even if a number of DSLANTMs are somehow coupled to share one CLT, there lacks a simple and inexpensive method and/or configuration to identify each individual DSLANTM for accurate communication with the network. What is needed is a new type of configuration that allows the sharing of a CLT with a number of DSLANTMs and provides simple and inexpensive identifications of individual DSLANTM.
The present invention provides a method and system for sharing resources in a system, which includes a computer and peripheral computer devices.
The present invention also provides a simple and inexpensive method to identify computer peripheral devices that are coupled to a computer or network communication system in a daisy chain configuration.
The present invention further provides a communication method and system which includes Digital Subscriber Line Access and Network Testing Multiplexer (DSLANTM) and co-located, peripheral DSLANTMs that share a single Copper Loop Tester provided with the DSLANTM, resulting in a highly space and cost efficient system.
The present invention still further provides a system that is adapted to facilitate the identification of computer peripheral devices. The system includes a computer with a communication port and a first switch; and a plurality of computer peripheral devices coupled to the computer in a daisy chain. The first switch has an open and a closed position. Each of the plurality of peripheral computer devices includes a bypass board having a sensor and a second switch thereon. Each of the second switches includes an open and a closed position. The plurality of peripheral computer devices is further coupled to the communication port of the computer. The computer is adapted to issue commands to the plurality of computer peripheral devices through the communication port. The second switch of each of the plurality of peripheral computer devices is adapted to connect to the daisy chain a succeeding one of the plurality of peripheral computer devices in the daisy chain when the second switch of the each of the plurality of peripheral computer devices is in the closed position, and to disconnect from the daisy chain the succeeding one of the plurality of peripheral computer devices in the daisy chain when the second switch of the each of the plurality of peripheral computer devices is in the open position. The sensor of each one of the plurality of peripheral computer devices is adapted to detect a short circuit when the first switch is in a closed position and the second switches of the plurality of peripheral computer devices preceding the each one of the plurality of peripheral computer devices in the daisy chain are in closed positions.
The present invention further provides a method for identifying each of a plurality of computer peripheral devices coupled to a computer in a daisy chain. The computer includes a first switch and each of the plurality of computer peripheral devices includes a second switch. The second switch of each of the plurality of peripheral computer devices is adapted to connect to the daisy chain a succeeding one of the plurality of peripheral computer devices in the daisy chain when the second switch of the each of the plurality of peripheral computer devices is in a closed position, and to disconnect from the daisy chain the succeeding one of the plurality of peripheral computer devices in the daisy chain when the second switch of the each of the plurality of peripheral computer devices is in an open position. The method includes the step of: (a) opening the first switch and the second switches; (b) closing the first switch; (c) detecting a short circuit formed between the computer and each one of the plurality of computer devices; and (d) identifying one of the peripheral computer devices which detects the short circuit as the first identified peripheral computer device.
The above and additional advantages of the present invention will become apparent to those skilled in the art from a reading of the following detailed description when taken in conjunction with the accompanying drawings.